Lamp with integral cooling radiation



zFeb. 13, 1940.

G. rM. DINNlcK LAMP WITH INTEGRAL COOLING RADIATION Filed Dec. 30, 1938 www ATTORNEY Patented Feb.' 13, 1940 um wrm INTEGRAL cooLlNo nAnIA'rToN George M. Dinnick, Blocmiield, N. J., asslgnor to Westinghouse Electric t Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Anuman December so, 193s, sem No. 243.393 '1 cnam. (c1. 17e-1s) UNITED ySTATI-:s PATENT OFFICE The invention relates to incandescent electric lamps and particularly to such of the gas-filled 4type which is apt to have bulb blackening.

The principal object of my invention is to prevent the condensation of filament material on the portion of the container utilized for the. production of light.

Another object of my invention is to remove excess heat from incandescent electric lamps while in operation and thus provide a greater protection to the lamp parts and also to permit the utilization of a greater amount of energy! without danger to these same lamp parts. y

. Specifically, it is an object of my invention 15 to provide a metal portion or the lamp wan for the purpose of having a cooled portion in the natural or directed path of the inner gas currents within the tube so that any particle from the iilament will condense upon this metal por- 20 tion and not upon the portion of the container utilized for the projection of light therethrough. The transfer of heat through this metal portion also aids in protecting the other tube parts from overheating.

l Other objects and advantages oi' the invention will be apparent from the following description and drawing, in which:

Fig. 1 is a cross-section through a tube embodying the invention.

l0 Fig. 2 is a top elevational view of Fig. l.

Figs. 3 and 4 are partial views in cross-section illustrating modications of the invention disclosed in Fig. l.

In ordinary practice the metal evaporated 5 from the incandescent filament in a lamp is deposited on the bulb wall causing an appreciable loss in lumen output due to absorption of light by the deposited material. This light absorption also increases the bulb temperature in some D cases to such an extent that the glass softens or becomes distorted and blows out due to the difference between the atmospheric pressure and the pressure inside the lamp.

To diminish the amount of material deposited i on the bulb and consequentlyto improve the lumen maintenance and to reduce the bulb temperature, I propose to insert a metal casing portion for a portion of the insulating material in the type of lamp which is particularly subject l to bulb blackening.

In Fig. 1, I have disclosed the lamp. I 0 comprising an envelope or bulb I I mainly of translucent insulating material such as glass and mounted on a base indicated at I2 and enclosing a mount I3. The mount of the present embodiment comprises the dared tube I4 sealed to the bulb and provided with an exhaust tube I5 and lead-in conductors I1 and I 8A extending through the press from the base I2 and connected to the iilament Il. 'I'his filament I6 has supports I9, which are in turn, supported from an arbor 20 on the ilared tube I t.

It will be noted that the tube I0 has an elongated axial aligned casing supported on the base I2 at one end. The filament in the intermediate portion is for the projection of light through the translucent glass tube walls adjacent the lament. The upper end of the tube has a metal casing portion 2| preferably of copper and sealed with the well-known feather edge seal 22 to the glass portion oi' the tube container. This metal, while preferably of copper because of its high quality of heat transference, may be of other materials that seal to glass such as the ironnickel-cobalt alloy known under the trade name of Kovar and described in the patent to Howard Scott, No. 2,062,335, issued December 1, 1936. This metal casing portion 2l has preferably exterior fins 23 extending upwardly and also laterally as disclosed in Fig. 1 and in the top view disclosed in Fig. 2. The metal casing portion also preferably has an interior iin 2li as disclosed in Fig. l, and in dotted lines in Fig. 2, extending acrossthe center portion of the tube. The interior tip end 25 of this interior iin is preferably pointed or tapered and is located in axial alignment with the center portion of the filament. divides the interior portion of the metal into two compartments. The tube It is generally illied with an inert gas such as argon or nitrogen and under the heat of operation, dow or convection currents are created inside of the tube. The fins 23 provide a. natural radiation of the heat from the interior of the tube and of course, this radiation may be aided by articial means such as a ian blowing air on the fins, or by water cooling. It is possible to substitute coils containing a liquid medium, such as Water, for the n 23. The cooled portion of the interior atmosphere will naturally drop downward along the inner surface of the tube wall as disclosed by the arrows 26, while the hot illament will send a hot current of gas upward as indicated by the arrows 21. The interior n 24 will aid in dividing this hot current of gas and directing it on either side thereof over the full inner surface of the metal casing 2| to effectively remove the heat therefrom. Any hot particle or vaporized portion of the illament carried along in this hot blast o! As disclosed in Fig. l, this interior fin.

gas,\will be deposited or condensed on .the inner surface of this metal casing 2| and will not be deposited on the lateral glass portion sides of the tube to darken this translucent portion. This translucent portion is, of course, translucent enough, generally, to be transparent. While I have disclosed one interior rib extending across the interior of the metal casing, other interior ribs might be used to further sub-divide the space at the top of the tube to direct the hot gas currents. From Fig. 2, it is apparent that the number of exterior fins 23 can be selected as desired.

In Figs. 3 and 4, I have made further modications in the metal casing portion 2| for more effectively directing the hot gas currents over` the cooled surface. The outer surface of the metal casing portion 2i formed into preferably a reentrant surface 3@ and have thus changed the interior n 2d into a gradually tapered or conical projection 3l. I have made the reentrant portion of the metal casing in this shape to maintain the thin walls for ready heat transference although it might be possible to use a thick wall at this place forming the cone projection. This conical projection 3| provides the gentle curve 32 for directing the gas currents over the surface of the metal casing portion and effectively cooling them. As a further modification, a metal guard 33 may be secured to the inner surface of the metal casing portion 2| to protect the feather seal 22. This guard, as shown, is held in place by friction although other fastening means could be utilized. This guard will prevent heat directly striking the seal and will conduct this heat to the main body of the metal casing.

In Figs. 3 and 4, I have also illustrated the type of incandescent electric lamp used for projection purposes and consequently generally us- L ing an extremely bright filament with its consequent release of considerable heat. I have also illustrated positive means for directing the hot gas currents from this lament towards the conical projection 3|. In Figs. 3 and 4, the lamp 50 comprises an envelope or bulb 8| with a base and mount similar to that of Fig. 1. The mount comprises a flared tube, similar to that illus- 4trated and designated as Il in Fig. 1, being sealed to the bulb and provided with an exhaust tube and an arbor or button 55 extending from the press. Leading-in conductors extend through the press from the base and connect with relatively rigid inner supporting leads 59 and 68 which may be formed of nickel or other suitable material with their normally lower ends embedded in the press. In this embodiment, the normally upper or free ends of the supporting leads 59 and 69 are connected by wires 8| and 62, the outer ends of which are spot welded thereto as indicated at 83 and 64 and the inner ends of which are embedded in an insulating member or bridge 65 which may be a piece of glass cane. Depending from the insulator 65 are a plurality of supporting members 66, 61, 88, 89, and 10, the number depending on how many coiled sections the lament 1| contains. In the present embodiment, the coiled filament 1| comprises eight coiled sections which are connected by intersection loops and staggered, so that four are disposed in one normally vertical plane and four in a normally vertical plane parallel thereto and so spaced that, in plan, they lie at theA vertices or isosceles triangles.

The upper uncoiled portions of the connected sections of nlament 1| are draped over the. hooked or doubled-over lower ends of members 88 to 10 inclusive, as illustrated, and the extreme coiled end sections 12 and 13 forced over connecting members 14 and 15, the outer ends of which are desirably spot welded to the support- 5 ing leads 59 and 68 respectively. Outer coils 16 and 11 may be screwed over the coiled. end portions 12 and 13 for short-circuiting the turns thereof to improve the uniformity of rating.

In order to hold the filament 1| in position between the leads 59 and G0 and at the same time avoid strains due to expansion and contraction of the metal parts of the lamp, a light bridge assembly 18 is provided, which preferably comprises an insulating portion 19 preferably 15 vformed of a piece of glass cane, and end wires 88 and 8l, the inner ends of which are embedded in an insulator 19 and the outer ends of which normally extend diagonally outward and upward and are formed with eyes or loops 82 and 88 to receive the supporting leads '59 and S9 respectively. 'Ihe eyes, or loops 82 and 83 are desirably adjusted so as to slide on the leads 59 and 6U with the avoidance of binding, even when the bridge device 18 ls slightly tilted with respect to said leads.

Y The bridge device 18 is normally suspended from the filament 1| by having members 84, 85, 88, and 81, the lower ends of which are embedded in the insulator 19 and the upper ends 30 of which are bent to hook over lthe loops formed between the lower portions of the coiled sections of filament 1|.

In order to prevent undesired tilting of the bridge device 18, when the lamp is inclined from its normal vertical base-down position', the insulator 19 is desirably provided with a bottom guide 88 slidably cooperating with the wire 89 extending upward from. the arbor 55.

Inasmuch as the lamp illustrated is of the type in which the filament is operated at a very high temperature to give a great amount of light with a relatively short life, the filament is desirably surrounded by an inert gas to reduce vaporization from the lament. Nevertheless, vaporization takes place and I have provided the metal portion 2| hitherto described, for the purpose of condensing this vaporized material or sputtered particles thereof and in addition, I have provided means for directing any such material onto this metal portion of the tube wall. In particular, I employ plate means comprising a pair of desirably imperforate plates 90 and 9| formed of metal such as nickel or molybdenum, which plates are desirably mounted so as to normally extend above and lie on either., side of the filament as shown most clearly in Figs. 3 and 4. For that purpose, the plates 90 and 9| are secured to the ends of a wire 92, as by spot welding, which wire is looped over the insulating bridge member 65 and supported therefrom as by being spot welded to a spud 93 extending upwardly from the approximate mid-portion thereof. In order to improve the connection between the wire 92 and the spud 93, the curved upper portion of the said wire preferably has first applied thereto a metallic ux which may consist of a coil 94 of relatively fine wire.

As illustrated, the plates 90 and 9| are desirably disposed so that their lower edges are slightly above the upper ends of the coil 1|, said plates being desirably inclined with respect to one another so that the included. angle is from about 20 to 30 degrees.

' As illustrated, the lower edges of the plates 75 may be separated about sixteen millimeters, and the top edges about eight millimeters, although the size of the plates, and the spacing thereof. desirably varies in accordance with the size of the light source in the enclosing bulb. The wire 92 is desirably extended between its curved Dortion and where it is connected to the plates Ol and 9|, so that the plates are properly positioned with respect to the filament.

In Fig. 4, the side view of the tube is shown to illustrate that each plate 90 and 9| preferably has its side edges flanged inwardly, as indicated at 95 and 96 so as to close up some of the space left between said edges and thereby improve the collecting characteristics of the plates.

. From the foregoing disclosure. it will be seen that means are provided in the incandescent lamp structure of Figs. 3 and 4 by these plates, for directing the gas currents towards the pro- Jecting cone 3| as indicated by the arrows in Fig. 4. The interior surface of the metal casing portion-is shaped as will be apparent from the drawing, for eil'ectively cooling this hot gas current and removing therefrom any sputtered or vaporized lament particles.

It is apparent that still further modications might be made in the preferred embodiments illustrated in the drawing without departing from the spirit of the following claims.

I claim:

1. A lamp comprising a iilament, a casing with an inert gaseous atmosphere enclosing saidv filament and having a translucent portion adjacent said iilament and a metal portion sealed to said translucent portion, said metal portion having interior i'ins.

2. A lamp comprising a filament. a casing with an inert gaseous atmosphere enclosing said iilament and having a translucent portion adjacent said lament and a metal portion sealed to said translucent portion, said metal portion having interior and exterior fins. v

3. A lamp comprising a base on one end and 5 a casing at the middle and other end, said middle having a translucent part of the casing and said other end having a metal part of the casing, ns on said metal part, and an inert gaseous atmosphere in said casing. 1o

4. A lamp comprising an extended axially aligned casing, a gaseous atmosphere therein, a filament along the axis of said casing, means directing the v gaseous atmosphere currents. heated by said lament, along the axis 'of said 15 tube, and a metal portion of. thecasing terminating the axis of the casing towards which said gaseous atmosphere currents are directed.

5. A lamp comprising a filament, a casing with an inert gaseous atmosphere enclosing said iliament and having a translucent portion adjacent said iilament and a metal portion sealed to said translucent portion, said metal portion having an interior reentrant surface.

6. A lamp having a base, a casing with an inert gaseous atmosphere supported by said base, a filament within the casing, said casing being translucent about said ilament and the opposite end of said casing from said base being of metal.

7. A lamp having a base, a casing with an inert gaseous atmosphere supported by said base, a lament within the casing, said casing being translucent about said filament and the oppositev end of said casing from said base being of metal, and having a reentrant surface having a projec- 35 tion towards said lament.

GEORGE M. DINNICK. 

